1. Technical Field
The present invention relates to a vibration element manufacturing method, a vibration element, an electronic device, an electronic apparatus, and a moving object.
2. Related Art
Hitherto, in order to form the three-dimensional shape or movable structure of a vibration element or the like of an acceleration and angular velocity sensor, micromachining to which a photolithography technique or an etching technique which is a technique for manufacturing a semiconductor device is applied has been used. The outward shape of the vibration element including vibrating arms is formed by etching a substrate using a metal film provided by a photolithography technique and a plating technique as a mask. In addition, when the cross-sectional shapes of the vibrating arms are asymmetric with respect to each other, the vibration element causes a deterioration in vibration characteristics, and thus is required to form the outward shape thereof with a high degree of accuracy. For example, JP-A-2013-207332 discloses a manufacturing method of forming an outward shape of a vibrator element and a recessed portion of a vibrating arm using dry etching. Thereby, it is possible to form the outward shape of the vibrator element with a high degree of accuracy.
However, the use of dry etching allows a high-accuracy outward shape to be formed, but since the film of a metal mask is reduced during the dry etching, it is necessary to form a thick metal mask requiring a more complex process than in a metal mask for wet etching. In the manufacturing method disclosed in JP-A-2013-207332, at least two-times dry etching is required, the number of processes of manufacturing a vibration element increases, and productivity drops, which results in an increase in manufacturing costs. In addition, when the recessed portion is formed using dry etching, product materials generated due to an etching gas, a material to be etched (substrate), and the like are deposited on the inside surface of the recessed portion, which leads to a problem of a drop in yield rate when electrodes are formed in the recessed portion.